Seriatopora hystrix variable temperature study (SHVTS)
Field sites of Southern Taiwan with their temperature profiles.
Take-home message: Corals from naturally variable reefs don’t just survive temperature swings—they may actually perform better because of them.
ChatGPT overview:
A S. hystrix nubbin used in the SHVTS.
This paper represents one of the earlier attempts to experimentally mimic the natural thermal variability experienced by corals in the field rather than relying on static “high-temperature” stress experiments. Using a laboratory-based reciprocal transplant design, the authors collected Seriatopora hystrix colonies from two reefs in southern Taiwan—one exposed to episodic upwelling and rapid temperature fluctuations, and another with comparatively stable temperatures—and exposed them to either constant 26 °C conditions or a highly variable 23–29 °C regime that replicated natural upwelling cycles. Rather than inducing bleaching, the fluctuating treatment actually enhanced several indicators of photosynthetic performance, including chlorophyll a, maximum quantum yield (Fv/Fm), and expression of key Symbiodinium photosynthesis genes such as rbcL, psI, and pgpase. The findings suggested that moderate thermal variability may stimulate or “train” the photosynthetic machinery of the coral-algal symbiosis rather than simply stress it, especially in corals historically exposed to variable environments. Methodologically, the study was especially important because it integrated physiology, molecular biology, and environmental realism into a single framework, helping move coral thermal biology away from overly simplistic heat-stress paradigms and toward a more nuanced understanding of acclimatization and phenotypic plasticity in reef corals.
Topside view of Houwan, the non-upwelling site
Houbihu, the upwelling site from which half of the S. hystrix colonies were collected.
near Houbihu, Nanwan, Taiwan
My version: Briefly, corals from an upwelling site (Houbihu) and a non-upwelling site (Houwan) in Southern Taiwan were exposed to either upwelling-simulating (i.e, "variable;" 23-29ºC over a 6-hr period) or stable (26ºC) temperature regime for one week, and a variety of physiological and molecular-scale parameters were assessed. All data have been posted below. In a nutshell, even corals exposed to their “non-native” temperature conditions (e.g., non-upwelling reef corals exposed to variable temperatures) performed well, so we decided to look into their cells to see how such acclimation was achieved. Spoiler alert: it has to do with endosymbiont Golgi-mediated lipid and protein trafficking.
1. For the description of the original SHVTS experiment, please see this manuscript.
Seriatopora hystrix nubbins grown in suspension (they are on fishing line, not the bottom of the plastic basket).
2. Here is a brief description of the library preparation methods. For basics on next generation sequencing chemistries, check out this (old!) Power Point presentation. For a huge fasta file of the contig sequences, please click here.
Yes, there is a bunny in the tank room.
3. For more molecular-scale data on these same samples, please see this manuscript.
4. There was also an interest in knowing how the transplantation out of the field and into the aquarium affected the experimental corals, a topic discussed in this manuscript.
5. An analysis of proteins over-expressed by samples of the stable temperature treatment relative to those of the variable temperature treatment can be found in this book chapter.
6. An analysis of proteins differentially concentrated between conspecifics of the two study sites, Houwan and Houbihu, can be found in this manuscript. The differentially concentrated proteinscan be found in list form here.
7. Finally, a large-scale comparison of the transcriptome vs. the proteome was conducted, andessentially zero congruency was found between gene and protein expression. The manuscript can be downloaded here.
8. In 2020, I used a more contemporary, label-based proteomic approach (iTRAQ) to attempt to corroborate the 2D gel-derived findings. The manuscript can be accessed here, with the mass spectrometry data found here (MassIVE) or on the Proteome Xchange repository (accession: PXD020679).
I have nearly published all of the data associated with this project. We even tested the physiological condition of corals in the field vs. those used in the experiments (in this manuscript). Here are the associated data files (this is a work in progress):
1. Here is a JMP file for all data for the 12 RNA-Seq samples only. The associated raw data can be found here.
2. Field data from the sampling sites: Houbihu (upwelling) and Houwan (non-upwelling).
A: Houbihu and Houwan temperature data. Condensed into monthly means.
B: Wanlitong (near Houwan) light data.
C: Houbihu light data.
3. Tank data.
A: Tank temperatures. In JMP format.
B: Light data (photosynthetically active radiation).
C: Light data averaged across week-long experiment (JMP).
C: Light data-in situ vs. ex situ.
Real-time PCR data for four Symbiodiniaceae genes targeted as part of the first publication describing this experiment (Mayfield et al. 2012 J Exp Biol). download
For a PCA featuring all expressed mRNAs (RNA-Seq), please scroll to the interactive plot at the bottom of the page.